make json-rpc mode work with linked devices

see #224

src/scripts/jsonrpc2-helper.go

@@ -10,6 +10,8 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"github.com/gabriel-vasile/mimetype"
+	"encoding/json"
 )
 
 const supervisorctlConfigTemplate = `
@@ -30,7 +32,38 @@ stdout_logfile_backups=10
 numprocs=1
 `
 
+func isSignalCliLinkedNumberConfigFile(filename string) (bool, error) {
+	fileExtension := filepath.Ext(filename)
+	if fileExtension != "" {
+		return false, nil
+	}
 
+	mimetype, err := mimetype.DetectFile(filename)
+	if err != nil {
+		return false, err
+	}
+	if mimetype.String() == "application/json" {
+		return true, nil
+	}
+	return false, nil
+}
+
+
+func getUsernameFromLinkedNumberConfigFile(filename string) (string, error) {
+	type LinkedNumberConfigFile struct {
+		Username string `json:"username"`
+	}
+	bytes, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return "", err
+	}
+	var linkedNumberConfigFile LinkedNumberConfigFile
+	err = json.Unmarshal(bytes, &linkedNumberConfigFile)
+	if err != nil {
+		return "", err
+	}
+	return linkedNumberConfigFile.Username, nil
+}
 func main() {
 	signalCliConfigDir := "/home/.local/share/signal-cli/"
 	signalCliConfigDirEnv := utils.GetEnv("SIGNAL_CLI_CONFIG_DIR", "")
@@ -58,9 +91,27 @@ func main() {
 			continue
 		}
 		filename := filepath.Base(item.Name())
-		if strings.HasPrefix(filename, "+") {
+		isSignalCliLinkedNumberConfigFile, err := isSignalCliLinkedNumberConfigFile(signalCliConfigDataDir + "/" + filename)
+		if err != nil {
+			log.Error("Couldn't determine whether file ", filename, " is a signal-cli config file: ", err.Error())
+			continue
+		}
+
+		if strings.HasPrefix(filename, "+") || isSignalCliLinkedNumberConfigFile {
+			var number string = ""
 			if utils.IsPhoneNumber(filename) {
-				number := filename
+				number = filename
+			} else if isSignalCliLinkedNumberConfigFile {
+				number, err = getUsernameFromLinkedNumberConfigFile(signalCliConfigDataDir + "/" + filename)
+				if err != nil {
+					log.Debug("Skipping ", filename, " as it is not a valid signal-cli config file: ", err.Error())
+					continue
+				}
+			} else {
+				log.Error("Skipping ", filename, " as it is not a valid phone number!")
+				continue
+			}
+
 			fifoPathname := fifoBasePathName + strconv.FormatInt(ctr, 10)
 			tcpPort := tcpBasePort + ctr
 			jsonRpc2ClientConfig.AddEntry(number, utils.ConfigEntry{TcpPort: tcpPort, FifoPathname: fifoPathname})
@@ -97,9 +148,6 @@ func main() {
 			if err != nil {
 				log.Fatal("Couldn't write ", supervisorctlConfigFilename, ": ", err.Error())
 			}
-			} else {
-				log.Error("Skipping ", filename, " as it is not a valid phone number!")
-			}
 		}
 	}